Systems and methods for drying and cleaning an aerial lift electrically insulated boom

ABSTRACT

A system is provided for use with an insulated boom section of a bucket truck. The system includes a source of high volume and pressure, dry air; one or more interior air diffusers connected to the source of high volume and pressure, dry air to direct the air into an interior of the insulated boom section. One or more exterior air diffusers connected to the source of high volume and pressure, dry air direct the air to along an exterior surface of the insulated boom section. A method is also provided for cleaning or drying both the interior and exterior surfaces simultaneously of an insulated boom section of the boom of a bucket truck. The boom of a bucket truck is further provided in another aspect that includes at least one insulated boom section, a source of high volume and pressure, dry air, one or more interior air diffusers and one or more exterior air diffusers. A pre-heating air heater may be removably mounted into the boom.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from U.S. Provisional PatentApplication No. 62/574,005, filed on Oct. 18, 2017 and Canadian PatentApplication No. 2,986,535 filed on Nov. 23, 2017, both entitled,“Systems and Methods for Drying and Cleaning An Aerial Lift ElectricallyInsulated Boom”, entireties of which are incorporated herein byreference.

FIELD OF THE INVENTION

The present invention relates to an apparatus for at least drying anelectrically insulated boom of an aerial lift, and methods for the useof same.

BACKGROUND

Maintenance of electrical transmission lines while they are energized isa common task that is completed using a variety of methods. One of thesemethods is direct contact, commonly referred to as “barehand”, where aworker is insulated from the ground and then energized at the samepotential as the live conductor. Using this method the worker candirectly touch and manipulate the energized components as long as theworker is insulated and maintains an adequate distance from areas ofdifferent potential such as the ground or adjacent phases.

Insulation from the ground is typically accomplished through the use ofan insulated aerial manlift commonly referred to as a bucket truck, suchas the insulated boom of a bucket truck, as seen for example in FIG. 1.Bucket trucks commonly have a boom 2 comprising multiple boom sections,hingedly connected together, to allow added height and articulation ofthe bucket 6. The final boom section 4 is typically the only sectionthat must be insulated. In a typical configuration all sections belowthe final boom section 4 may be made of steel with the final boomsection 4 leading to the bucket 6 made with a dielectric, for example alength of hollow fiberglass or other non-conductive material. Aninsulated section 8 may be used to isolate the metal boom elbow 4C.

Regardless of bucket truck or insulated boom design, maintaining thedielectric properties of the insulated section are key to ensuringsafety of the workers during barehand operations. During use,transportation, storage, etc. conductive particles from various sourcesincluding but not limited to soil, dust, salt, pollution, commonlycollect on the exterior and interior surfaces of the insulated boom. Thepresence of these contaminates, in small amounts, will not by themselvescause a dielectric failure. Moisture can also appear on the surfaces ofthe insulated boom as a result of dew point, humidity, andprecipitation, including rain, snow, fog or frost. Accumulation ofmoisture on the interior and exterior surfaces of the insulated boom incombination with these contaminants greatly decreases the surfaceelectrical resistance of the boom. As the surface resistance decreases,current flowing on the inside and outside of the insulated boom sectionincreases. At a certain point this current becomes so great that theinsulated boom in fact becomes a conductive path to ground and acomplete electrical failure or “flashover” can occur.

Contaminants on the surfaces of the insulated boom create areas ofdifferent resistance or conductance. If the distance between these areasis great enough and the insulation is clean enough, no current willflow. However with the addition of some moisture, resistance toconduction between the areas can be overcome and current will flow.

To avoid conducting current, insulated booms may be designed to determoisture and for ease of cleaning. The outer surface of the boom isoften smooth and coated with hydrophobic wax in order to resist thebuildup of moisture and contaminants and to promote beading in the eventof moisture build up. In some designs, the interior of the boom issealed and a desiccant, such as silica gel is placed within the boom tocollect moisture. However, most booms in common use are not sealed, asthe interior spaces of the booms are often used to contain componentsfor the control of the boom and bucket such as hydraulic lines,fiber-optic cables, and bucket leveling rods. To allow access to thesecomponents and to allow them to move as the bucket moves, the insulatedsection of the boom hereinafter referred to as the insulated boom, isleft unsealed and open at either end.

Prior to and during barehand operations, the insulated boom iselectrically tested and monitored for current leakage. Industrystandards usually allow 1 micro-amp per kV of the voltage to ground. Tomeasure leakage current, metal collector bands are typically located atthe bottom end of the insulated section of the boom around the outsideand inside of the boom. Also all hoses, fiber optic links and levelingrods have metal bands to collect any leakage current. All thesecollector bands are connected together and run through a current leakagemeter to ground.

In a typical barehand procedure, the upper end of the boom is firstenergized by contacting one phase of the energized powerline and theleakage current of the insulated section of the boom is measured. If theleakage current is below the maximum level, the boom is left in placefor three minutes and the leakage current is checked again. If theleakage current is above the maximum level, then the boom is immediatelyremoved from the line and cleaned and dried. Usually high readings arethe result of moisture and contamination on the inside and outsidesurfaces of the boom. Once the boom has been cleaned and dried it isretested. If leakage current is below the maximum level, then barehandwork can proceed.

During the barehand work, the leakage current is constantly monitoredand an audible alarm will sound if a preset leakage current value isexceeded. The normal leakage current value is usually well below themaximum allowed. Changing moisture conditions can cause the leakagecurrent to increase and set off the alarm. If this occurs the boom isremoved from the line, cleaned, dried and retested before work can beginagain.

Controlling moisture levels on the interior and exterior surfaces of theboom is critical. In some jurisdictions or for some power utilitycompanies work cannot be performed when humidity is above 80%. Duringperiods of rapid temperature change, especially in humid environments,condensation will begin to form on the interior and exterior surfaces ofthe boom. If this occurs work must be halted, or cannot begin until thesurface resistance of the boom has been restored. The surface moistureis wiped off using a clean rag, and the interior moisture must beallowed to dry. This is typically accomplished by raising the insulatedsection of the boom to a near vertical position and allowing ambientairflow to eventually dry the interior of the boom. The boom may also bepositioned in the sunlight if possible, in order to warm and facilitateevaporation from the boom as quickly as possible.

The result is that work cannot be completed during these periods ofprecipitation or humidity. Often an entire crew of people can spendhours waiting for conditions to improve and waiting for the interior andexterior of the insulated boom to dry before work can begin, causinginsufficient and costly downtime.

In published US Patent Application, publication number US 2004/0255986,a superheated steam is flowed through a boom, then concentrated into apressurized jet at the output end of the boom so as to be directed ontoequipment to be cleaned.

U.S. Pat. No. 4,877,422 teaches drying the interior of an insulated boomby supplying a constant stream of non-heated air from an air source intothe boom during the course of the barehand or other operations onconductors. Air exiting from an outlet end the boom is removed or purgedto atmosphere and may be monitored for humidity. The air supply may be acompressor on the aerial lift truck. There is no suggestion of using anairstream on the outside of the boom, nor of re-utilizing the air streamflowing from the interior of the boom.

SUMMARY

A system is provided for use with an insulated boom section of thebucket truck so as to dry the insulated boom section. The systemcomprises a source of high volume and pressure dry air; one or moreinterior air diffusers positioned at a first end of the insulated boomsection and connected to the source of high volume and pressure dry airto direct the air into the interior of the insulated boom section so asto flow from the first end to a second, opposite, end of the insulatedboom section. One or more exterior air diffusers are positioned at thefirst end of the insulated boom section and connected to the source ofhigh volume and pressure dry air to direct the air to along an exteriorsurface of the insulated boom section, from the first end to the secondend of the insulated boom section.

In a further embodiment the system further comprises one or more ventspositioned at the second end of the insulated boom section. The ventsare in fluid communication between the interior and the exterior surfaceof the insulated boom section. A collector-diffuser is positioned at thesecond end of the insulated boom section to collect the air exiting theinterior of the insulated boom section from the one or more vents and todiffuse the exiting air downwards along the exterior surface of theinsulated boom section, in a direction from the second end to the firstend. Preferably the second end of the boom is the distal end, distalfrom an elbow on the boom, and adjacent the bucket.

In one embodiment, the source of high volume and pressure dry airincludes an electric heater-blower so as to both dry, heat and directthe airflow along the boom.

In a further embodiment, the source of high volume and pressure dry airincludes an air dryer so as to dry the air being blown along theinsulated boom section.

In a further embodiment, the system may also include one or moreconcentrator-diffusers positioned at intervals along the length of theinsulated boom section to concentrate the air travelling along theexterior surface of the insulated boom section and direct it furtheralong the exterior surface of the insulated boom section.

In a further embodiment, the system further comprises an air heater inconnection with the source of high volume and pressure dry air.

A method is also provided for drying both the interior and exteriorsurfaces simultaneously of an insulated boom section of the boom of abucket truck. The method includes the steps of providing a source ofhigh volume and pressure dry air; directing the high volume and pressuredry air from the source into an interior of the insulated boom sectionfrom a first end to a second, opposite, end of the insulated boomsection, and also simultaneously directing the source of high volume andpressure dry air from the source along an exterior surface of theinsulated boom section, from the first end to the second end of theinsulated boom section.

The boom of a bucket truck is further provided in another aspect of theinvention that includes at least one insulated boom section adjacent abucket of the truck, the insulated boom section comprising a first end,a second opposite end, an interior and exterior surface, a source ofhigh volume and pressure dry air, one or more interior air diffuserspositioned at the first end of the insulated boom section and connectedto the source of high volume and pressure dry air to direct a flow ofthe air into the interior of the insulated boom section from the firstend to the second opposite end; and one or more exterior air diffuserspositioned at the first end of the insulated boom section and connectedto the source of high volume and pressure dry air to direct a flow ofthe air to along the exterior surface of the insulated boom section,from the first end to the second opposite end.

It is to be understood that other aspects of the present invention willbecome readily apparent to those skilled in the art from the followingdetailed description, wherein various embodiments of the invention areshown and described by way of illustration. As will be realized, theinvention is capable for other and different embodiments and its severaldetails are capable of modification in various other respects, allwithout departing from the spirit and scope of the present invention.Accordingly the drawings and detailed description are to be regarded asillustrative in nature and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

A further, detailed, description of the invention, briefly describedabove, will follow by reference to the following drawings of specificembodiments of the invention. The drawings depict only typicalembodiments of the invention and are therefore not to be consideredlimiting of its scope. In the drawings:

FIG. 1 is a side elevational view of a conventional or prior art buckettruck with boom and bucket partially extended from the truck; such couldbe used with the present invention;

FIG. 2 is a side elevational view of a bucket truck with an insulatedboom, adapted to include an air dryer according to one embodiment of anair source of the present invention;

FIG. 3 is a side elevational view of the bucket truck of FIG. 2 with theboom retracted;

FIG. 4 is a side elevational view of the bucket truck of FIG. 3, showinga second embodiment of an air source;

FIG. 5 is a side elevational view of the bucket truck of FIG. 4, showinga third embodiment of an air source;

FIG. 6 is an enlarged, partially cutaway, side elevational view of theelbow, insulated boom, and bucket of FIG. 2 illustrating the air flowinside and along the outside of the boom according to one embodiment ofthe present invention;

FIG. 6A is an enlarged portion of the view of FIG. 6.

FIG. 7 is the side elevational view of the elbow, insulated boom andbucket of FIG. 6, illustrating air flow along the outside of theinsulated boom section and air flow inside the boom being collected atthe top and being redirected back downwards along the outside of theboom, showing a second embodiment of the present invention;

FIG. 8 is the side elevational view of the elbow, insulated boom andbucket of FIG. 7, illustrating air flow inside the insulated boomsection and air flow along the outside of the insulated boom and beingcollected and redirected along the outside of the boom and further beingcollected and redirected along the outside of the insulated boom,showing a third embodiment of the present invention; and

FIGS. 9A and 9B are side and front elevation views respectively of oneembodiment of an air diffuser of the present invention.

The drawings are not necessarily to scale and in some instancesproportions may have been altered in order to more clearly depictcertain features.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS

The following description of embodiments is provided by way ofillustration of an example, or examples, of particular embodiments ofthe principles of various aspects of the present invention. Theseexamples are provided for the purposes of explanation, and not oflimitation, of those principles and of the invention in its variousaspects.

Generally, with reference to FIGS. 2 through 9B, and with initialreference to FIGS. 6 and 7, a gas, preferably air, is directed along theinsulated boom section 4 of boom 2 so as to flow through the boominterior 4A, and simultaneously along the boom exterior 4B, of insulatedboom section 4 of boom 2. For purposes of this description, insulated isintended to mean electrically insulating, dielectric, or electricallynon-conducting. Before reaching the insulated boom section 4 of boom 2,the air is directed through air lines 10A along the boom interior 4A,and through air lines 10B along exterior surface 4B. Air flow can becontrolled by regulators and valves anywhere along the air lines 10A and10B. As depicted in at least FIG. 2, leading to the insulating boomsection 4, air lines 10A and 10B may, as shown, be mounted along theexterior of the boom 2, although this is not intended to be limiting.Preferably air lines 10A and 10B run from the base of the boom 2, to thebottom of the insulated section of the boom 4.

Alternatively air lines 10A and 10B may be combined in a single air line(not shown). The single air line may then split into two, separate anddedicated air lines, one for each of boom interior 4A and boom exterior4B at the base end of insulated boom section 4 and at such point theseparate streams of the air flow may be controlled by separateregulators and valves.

In order to maintain insulating qualities of the insulated boom section4, air lines 10A and 10B may preferably be comprised of electricallyinsulated hose or pipe. That is, the electrically insulated hose or pipeitself may be a dielectric material. Such electrically insulated hose orpipe may extend for example a full length from the air source, forexample on the back of the bucket truck, to insulated boom section 4, oralternatively, air lines 10A and 10B can be non-insulated from the backor rear of the bucket truck up to the insulated boom section 4, exceptthe air lines 10A and 10B can be electrically insulated along theinsulated boom section 8.

With references to the figures, the insulated boom section 4 may beprovided with one or more internal and external air diffusers 20, 22 todeliver air to boom interior 4A and exterior 4B, respectively. The airmay advantageously in one embodiment be warmed, dry air. Internal airdiffuser 20 distributes air equally to, around and along the boominterior 4A of insulated boom section 4. External air diffuser 22distributes air equally to, around, and along boom exterior 4B ofinsulated boom section 4. FIG. 9A depicts one embodiment of an externalair diffuser 22, and FIG. 9B is a cross section along line 9B-9B of FIG.6 showing an end view of both the internal air diffuser 20 and externalair diffuser 22. The internal air diffuser 20 comprises a diffusermanifold body 20 a that generally matches an internal circumference ofthe hollow cavity inside insulated boom section 4 and comprises one ormore internal nozzles 50. The external air diffuser 22 includes adiffuser manifold body 24 that encircles the circumference of theinsulated boom section 4 and defines an annular manifold feeding air tonozzles 28. For the purposes of the present invention, the term nozzleis used to include any opening, slot or aperture through which air canflow from the air lines 10A and 10B to the boom interior 4A or exterior4B, respectively. The air diffuser body 24 may in one embodiment, notintended to be limiting, be split in to two or more air lines 26 betweengas line 10B and manifold body 24. Air nozzles 28 encircle an externaldownstream surface or ring 24A on the downstream end of air diffuserbody 24. Nozzles are radially positioned in an array around ring 24A,such as with equal arc length segments between the nozzles, so as todirect air flow in the direction of arrows A in a substantially uniformflow around and along exterior 4B of insulated boom section 4.

While the figures show air diffusers 20 and 22 being proximate a bottomend 4C of the insulated boom section 4 of the boom 2, with air flowingin the direction of arrows A and B towards upper end 4D, such as towardbucket 6, of the insulated boom section 4, it would be well understoodby a person of skill in the art that air diffusers 20 and 22 may beplaced proximal the upper end 4D of the insulated boom section 4, andgas flow would in such case be in the opposite direction of arrows A andB, towards the bottom 4C of the insulated boom section 4. Further, morethan one of air diffuser 20 or 22 may be required along the length ofboom section 4. The length of boom section 4 may be such that the airflow required to dry the interior or exterior of boom section 4,requires sufficient pressure and/or volume that the forced air flow isdone in stages along boom section 4. Thus, a plurality of the diffusers20, 22 may be spaced, e.g. equally spaced, along boom section 4.

The boom interior 4A may conventionally, as described earlier, carry orcontain hydraulic hoses 30 and leveling rods 32. Consequently, flow ofgas within and along boom interior 4A flowing in the direction of arrowsB (shown as dotted lines in FIG. 6) is partially blocked or partiallyoccluded, thereby increasing the surface area to be dried. All surfaceswithin boom interior 4A must be dried. Thus, any partial blockageswithin boom interior 4A make the drying more difficult or at least moretime consuming as increased surface area must be covered and dried. Thepartial blockages may include the hoses and rods and any control anddata conduits, wires, optical fibers, bundles, etc. that may be requiredto traverse the length of boom interior 4A, for example for theoperation of the boom and bucket, connected equipment, winches and jibs,etc. Drying is, fortunately, assisted in that the rods, hoses, conduits,etc. extend longitudinally along boom interior 4A, thereby minimizingmoisture pockets in the lee, i.e. immediately downwind, behind thepartial blockages, which slow the drying by the air flowing in directionB.

The air flowing in boom interior 4A is injected into and along boominterior 4A from internal air diffuser 20. Although not shown, it willbe understood by one skilled in the art that to achieve drying air flowin direction B, in one embodiment interior air diffuser 20 may includeat least one manifold directing the air flow to nozzles within boominterior 4A which direct the high volume flow, advantageously underpressure as described below in direction B. For example the manifold forinternal air diffuser 20 may function similarly to manifold 24, and mayalso be annular to distribute the air flow to nozzles arranged in aspaced apart array, circumferentially around the interior base end ofboom interior 4A.

In one embodiment, air diffuser 20 is mountable into a port or otherwisethrough an opening in the lower elbow of the boom such as seen in FIG.6, where diffuser 20 is shown in dotted outline. Such an opening or portinto the elbow may be also used for removably mounting a blower, ceramicor other form of pre-heater or forced-air heater (collectively referredto herein as air-heater 21) into boom interior 4A, as better seen inFIG. 6A, for warming boom interior 4A when the boom is not in use; forexample at night. Pre-heating or pre-warming the boom interior 4A byheater 21 may reduce the time required for the air diffuser 20 tootherwise dry boom interior 4A ready for operation. The pre-warming ofthe interior 4A may also reduce the time required to dry the exterior ofthe boom using air diffuser 22 for example. Heater 21 may be anelectrical heater, for example powered by a small portable generator(not shown). Heater 21 may be independently mountable into boom interior4A, and may preferably be removable therefrom so as to be removed fromthe boom during its operation. For example, heater 21 may be mountedthrough a sealable port into one of the boom elbows, so as to directwarm air upwardly along boom interior 4A. If heater 21 is left runningfor example over-night while mounted into boom interior 4A, it may beremoved from the boom in the morning or otherwise prior to use of theboom. Heater 21 may also for example be mountable into a diffuser, e.g.diffuser 20, mounted in boom interior 4A so as to direct warm airthrough the diffuser and thereby into boom interior 4A.

The air may be any readily available inert gas, but is more preferablydry air. The air may be directed from the nozzles at either a highvolume and low pressure, or at a low volume and high pressure, or at ahigh volume and high pressure. The movement of air simultaneouslythrough the boom interior 4A and along the boom exterior 4B serves toprovide both a drying effect to decrease moisture within boom interior4A, and on the boom exterior 4B of the insulated boom section 4, as wellas to physically move contaminants and any surface charges off theinsulation and away from the grounded sections of the bucket truck. Theair may advantageously be dried or dehumidified prior to being directedwithin and along the insulated boom section 4. Further preferably, theair may be heated to aid in evaporation and removal of moisture.

Any number of sources maybe used to provide the dried and optionallyheated air. One or more electric style air heater/blowers may beinstalled on insulated boom section 4, at the bottom end 4C, and may bepowered by the on-board electric power, battery, or generator, asexamples. Alternatively, compressed, dried and optionally heated, aircould be delivered via air lines 10A, and 10B to the bottom end of theinsulated boom section 4 by an external air compressor driven by a gas,diesel, hydraulic or electric motor. Such an air compressor could beplaced on the top of the bed of the bucket truck or in a towed trailer,but in either case the air compressor would be a separate portable unit.Dried and optionally heated and compressed or pressurized air would bedelivered by means of an air hose installed within or alongside thelower boom sections and then delivered by means of a regulator and avalve for example located at the lower end of the insulated boom section4 of the boom or at the air compressor.

In one embodiment of the present invention, illustrated in FIG. 3, airis provided to both of the internal surface 4A and external surface 4Bof the insulated section of the boom 4 by means of an air compressor 14,air dryer 16, and optionally also a heater 18 to deliver, warmed ifrequired, dry air.

The air compressor 14 may be of any type known in the industry includingthose run by diesel, gas, electricity or hydraulically. The aircompressor 14 is preferably mounted on a deck of the bucket truck, butcan also be provide on a separate trailer or vehicle (not shown).Connected to the air compressor 14 is the air dryer 16 to remove anymoisture from the air. The air dryer 16 may be connected in series withthe air compressor 14. The air dryer can be a standard air dryer or itcan comprise an electric or gas heater to dry the air thereby removinghumidity from the air.

In an optional embodiment, a heater 18 can be connected to a downstreamend of the air dryer to warm the compressed or pressurized and driedair, to increase the effectiveness of removing moisture from the boominterior 4A and exterior 4B. The air can be delivered to a bottom end ofthe insulated boom section 4 via the air lines described above.

In a second embodiment of the present invention, which is not intendedto be limiting, the supply of air over, across and in contact with theexterior 4B of the insulated boom section 4 comes from an air compressor14, air dryer 16, and an optional heater 18. In this embodiment, aninternal electric heater/blower 34A (shown in FIGS. 4 and 5 as replacingair diffuser 20) is used to blow dry, warm air to the boom interior 4A.The internal electric heater/blower 34A may be for example powered bybatteries, the truck's electrical system, or a separate gas or dieselgenerator 36 (FIG. 5) mounted on the truck deck or mounted on a separatetrailer or vehicle. Internal or external power lines 38A, 38B, alsocalled electric cables, supply power to the internal electricheater/blower 34A from the generator 36. The internal electricheater/blower 34A is preferably located at the bottom end 4C of theinsulated boom section 4 of the boom 2 to deliver dry, and optionallywarmed, air to an interior 4A of the insulated boom section 4. More thanone internal electric heater/blower 34A could also be used at the bottomof the insulated section 4 of the boom 2. In such embodiment, theinternal electrical heater/blower 34A may serve the function of anexterior air diffuser as well.

As before, the air compressor 14 is preferably mounted on a deck of thetruck, but can also be provide on a separate trailer or vehicle (notshown). Connected to the air compressor 14 is the air dryer 16 to removeany moisture from the air. In an optional embodiment, a heater 18 can beconnected to a downstream end of the air dryer to warm the compressedand dried air, to increase the effectiveness of removing moisture fromthe boom interior 4A and boom exterior 4B. The air can be delivered to abottom end of the insulated boom section 4 of the boom 2, via anexternal airline 10B alongside the lower sections of the boom 2. Airflow may be controlled by a regulator and valve anywhere along theexternal airline 10B. Again, an external air diffuser 22 is used todirect the air flow along an external surface 4B of insulated boomsection 4 of the boom 2.

In a third embodiment, as illustrated in FIG. 5, air is delivered toboth the boom interior 4A and boom exterior 4B of the insulated boomsection 4 of the boom 2 by means of electric heater/blowers 34A, 34B. Anexterior electrical heater/blower 34B delivers dry air, warmed ifrequired, to the exterior surface of boom exterior 4B. More preferably,the exterior electrical heater/blower 34B serves as the externaldiffuser as well as the heater/blower.

In this third embodiment, to dry the boom interior 4A, an internalelectric heater/blower 34A is also used to blow, dry warm air through,and when positioned in an in-use position, up through the boom interior4A. These electric heater/blowers 34A, 34B may be powered by batteries,the electrical system of the truck or optionally by a separate gas ordiesel generator 36 mounted on a deck of the truck or mounted on aseparate trailer or vehicle.

Power to the electric heater/blowers may be delivered to the bottom ofthe insulated boom section 4 of the boom 2 via one or more electriccables 38A, 38B alongside or inside the lower sections of the boom 2.More than one electric heater/blower 34A, 34B could also be used at thebottom of the insulated boom section 4 of the boom 2. Air flow can becontrolled by adjustable switches anywhere along the electric cables38A, 38B, to the insulated boom section 4 of the boom 2.

As described above and again, with reference to FIGS. 6, 7 and 8, air isdelivered and flows within, and over the external surface of, theinsulated boom section 4 of the boom 2. While FIGS. 6, 7 and 8illustrate air diffusers 20 and 22, another aspect of the invention isthat the flow configurations of these figures can equally be achieved byuse of either an internal electric heater/blower 34A in connection withair flow to an interior 4A of the boom 2, or an external electricheater/blower 34B in connection with air flow on an exterior 4B of theboom 2, or a combination of both internal electric heater/blower 34A andexternal electric heater/blower 34B. Moreover, any combination of theembodiments of FIGS. 6, 7 and 8 may be used together for the purposes ofdelivering and distributing air flow within and along the insulated boomsection 4.

With reference to FIG. 6, in a first embodiment, air flow through theboom interior 4A and air flow along boom exterior 4B of the boom 2 areboth allowed to dissipate upwardly as a discharge from the upper end 4Dof the boom 2, which is at or proximate bucket 6. As described above, inFIG. 6, the solid arrows A represent air flow along the exterior surfaceof boom exterior 4B and dashed arrows B represent air flow within boominterior 4A, including along interior surfaces of insulated boom section4.

With reference to FIG. 7, in a second embodiment, air flow from boominterior 4A may be collected at top or upper end 4D of the insulatedboom section 4 in an internal collector/diffuser 40. The collected airflow can then be redirected 180 degrees in direction C back down alongthe exterior boom surface 4B as the internal air flow in direction B isredirected by collection/diffuser 40 along boom exterior 4B by theinternal collector/diffuser 40. Air collection and redirection, in arevolving cycle, may be repeated multiple times. In this embodiment,energetic air flow is thus directed over the boom exterior 4B of theinsulated boom section 4 by the two opposed facing external airdiffusers 22 and 40. This of course assumes that the internal air flowin direction B from air diffuser 20 is sufficiently energized(sufficiently high volume and/or high pressure) within the confines ofboom interior 4A so that even with pressure losses along boom interior4A, the air flow has sufficient energy once redirected by air diffuser40 to assist in moisture removal by blowing back along boom exterior 4B.

To provide communication between the insulated boom interior 4A and theinsulated boom exterior surface 4B one or more vents may be formed atthe end of the insulated boom section 4 near the corona ring 46. In afurther preferred embodiment, one or more vanes (not shown) may be fixedinto each vent to drive dry high-pressure air from the insulated boominterior 4A to the insulated boom exterior surface 4B of the insulatedboom section 4 of the boom 2. In environments with light precipitationor high humidity, the insulated section of the boom 4 between the coronaring 46 and the bottom of the boom 4C, is the most critical. The airdiffuser is most preferably located near the corona ring to drivehigh-pressure air exiting the insulated boom interior 4A back along theinsulated boom exterior 4B of the insulated boom section 4 at theenergized end 4D.

With reference to FIG. 8, in a third embodiment, one or more externalcollectors/diffusers 44 can be installed along a length of the insulatedboom exterior 4B. More preferably the external collector/diffusers 44may be cone-shaped or frusto-conical (with the narrow end downstream),to gather air flow as it travels along insulated boom exterior 4B, andto re-concentrate the air flow and direct the air flow as are-concentrated flow flowing down stream further along the insulatedboom exterior 4B. This may be thought of a boosting the flow in stagesalong insulated boom section 4. Thus, the air flow is enhanced along thefull length of the exterior surface of the insulated boom section 4 ofthe boom 2, therefore enhancing drying and/or cleaning of insulated boomexterior 4B of insulated boom 44B.

In supplying air to the insulated boom section 4 of the boom 2, theinterior and exterior air lines 10A, 10B may be insulated, that is,dielectric, air hoses. Such air hoses may be plumbed through the boominterior 4A and may then be directed at specific points outwards ontothe boom exterior 4B.

The high pressure and/or high volume dry air delivered along insulatedboom section 4 serves to rapidly and simultaneously dry both theinsulated boom interior 4A and insulated boom exterior 4B and reducesthe wait time required before work can begin using the boom 2 forbarehand operations in an energized environment. The system may furtherprovide the insulated boom section 4 with interior and exterior dryingduring energized work in adverse conditions such as during periods ofhigh humidity.

The present system for providing and distributing high volume andpressure air along the exterior surface of the insulated boom furtherserves to strip charged particles and contaminants from the surface ofthe insulation and drive them off the surface of the boom and away fromthe grounded end of the insulated section. By continually removinginterior and exterior moisture and exterior surface charge andcontamination, the insulated boom inhibits areas of differing potentialfrom developing that may lead to dielectric failure of the insulatedsection. Removing these charged particles from the surface of theinsulated boom section 4 will also work to decrease leakage currentmoving along the insulated section of the boom.

The previous description of the disclosed embodiments is provided toenable any person skilled in the art to make or use the presentinvention. Various modifications to those embodiments will be readilyapparent to those skilled in the art, and the generic principles definedherein may be applied to other embodiments without departing from thespirit or scope of the invention. Thus, the present invention is notintended to be limited to the embodiments shown herein, but is to beaccorded the full scope consistent with the claims, wherein reference toan element in the singular, such as by use of the article “a” or “an” isnot intended to mean “one and only one” unless specifically so stated,but rather “one or more”. All structural and functional equivalents tothe elements of the various embodiments described throughout thedisclosure that are known or later come to be known to those of ordinaryskill in the art are intended to be encompassed by the elements of theclaims. Moreover, nothing disclosed herein is intended to be dedicatedto the public regardless of whether such disclosure is explicitlyrecited in the claims. No claim element is to be construed under theprovisions of 35 USC 112, sixth paragraph, unless the element isexpressly recited using the phrase “means for” or “step for”.

1. A system for use with an insulated boom section of a bucket truck,said system comprising; a. a source of high pressure, dry air; b. one ormore interior air diffusers adapted to be positioned at a first end ofsaid insulated boom section and adapted to be connected to said sourceof high volume and pressure, dry air to direct a first flow of said airinto an interior of the insulated boom section from the first end to asecond opposite end of the insulated boom section; and c. one or moreexterior air diffusers adapted to be positioned at the first end of saidinsulated boom section and adapted to be connected to said source ofhigh volume and pressure, dry air to direct a second flow of said air toalong an exterior surface of the insulated boom section, from the firstend to the second opposite end of the insulated boom section.
 2. Thesystem of claim 1, further comprising; a. said insulated boom section;b. one or more vents positioned at the second end of the insulated boomsection, and in fluid communication between the interior and theexterior surface of the insulated boom section; and c. acollector-diffuser positioned at the second end of the insulated boomsection to collect air exiting the interior of the insulated boomsection from the one or more vents and diffusing the exiting air alongthe exterior surface of the insulated boom section, from the second endto the first end.
 3. The system of claim 1, wherein said source of highvolume and pressure, dry air is an electric heater-blower.
 4. The systemof claim 3, wherein said electric heater-blower further serves as one ormore of the internal air diffuser and the external air diffuser.
 5. Thesystem of claim 1, wherein said source of high volume and pressure, dryair is a compressor and an air dryer.
 6. The system of claim 1, furthercomprising, when the system of claim 1 is mounted on the boom, one ormore concentrator-diffusers positioned at intervals along the length ofthe insulated boom section to concentrate air travelling along theexterior surface of the insulated boom section and direct it furtheralong the exterior surface of the insulated boom section.
 7. The systemof claim 1, further comprising a first air heater in connection with thesource of high volume and pressure, dry air.
 8. The system of claim 1wherein said first end of the insulated boom section is a bottom end ofthe insulated boom section and said second opposite end of the insulatedboom section is an upper end of the insulated boom section.
 9. Thesystem of claim 1, wherein said internal air diffuser comprises anannular manifold to direct and distribute air flow.
 10. The system ofclaim 1, wherein the internal and external air diffusers are adapted todirect the first and second flows, respectively, simultaneously.
 11. Thesystem of claim 1, wherein said external air diffuser comprises anannular manifold to direct and distribute air flow.
 12. The system ofclaim 11, wherein the annular manifold comprises one or more nozzles ona surface thereof.
 13. The system of claim 1 further comprising a secondair heater, said second air heater being removably mountable into a portinto the boom whereby the boom is pre-heated by the second air heater.14. The system of claim 13 wherein the second air heater is a forced-airheater
 15. The system of claim 14 wherein the port is at a lower end ofthe boom
 16. A method for drying or cleaning interior and exteriorsurfaces of an insulated boom section of an aerial lift truck, saidmethod comprising the steps of; a. supplying high volume and pressure,dry air; b. directing said high volume and pressure, dry air into aninterior of the insulated boom section so as to flow along the interiorin a first direction; and c. simultaneously directing said high volumeand pressure, dry air along an exterior surface of the insulated boomsection so as to flow along the exterior in a second direction.
 17. Themethod of claim 16, wherein a source of the high volume and pressure,dry air is an electric heater-blower.
 18. The method of claim 16 whereinsaid first and second directions are from a first end to a second,opposite, end of the insulated boom section.
 19. The method of claim 16,wherein a source of the high volume and pressure, dry air is acompressor and an air dryer.
 20. The method of claim 16, furthercomprising the steps of: a. concentrating air travelling in the seconddirection along the exterior surface of the insulated boom section atone or more intervals; and b. directing said concentrated air furtheralong the exterior surface of the insulated boom section between saidintervals.
 21. The method of claim 16, further comprising a step ofheating the high volume and pressure, dry air.
 22. The method of claim18, wherein directing air from said first end to said second, oppositeend comprises directing air from a bottom end of the insulated boomsection to an upper end of the insulated boom section.
 23. A buckettruck, comprising; a. at least one insulated boom section adjacent abucket of said truck, said insulated boom section comprising a firstend, a second opposite end, an interior and exterior surface; b. asource of high volume and pressure, dry air; c. one or more interior airdiffusers positioned at the first end of said insulated boom section andconnected to said source of high volume and pressure, dry air to directa flow of said air into the interior of the insulated boom section fromthe first end to the second opposite end; and d. one or more exteriorair diffusers positioned at the first end of said insulated boom sectionand connected to said source of high volume and pressure, dry air todirect a flow of said air to along the exterior surface of the insulatedboom section, from the first end to the second opposite end.
 24. Thebucket truck of claim 23, further comprising; a. one or more ventspositioned at the second end of the insulated boom section, and in fluidcommunication between the interior and the exterior surface of theinsulated boom section; and b. a collector-diffuser positioned at thesecond end of the insulated boom section to collect air exiting theinterior of the insulated boom section from the one or more vents anddiffusing the exiting air along the exterior surface of the insulatedboom section, from the second end to the first end.
 25. The bucket truckof claim 23, wherein said source of high volume and pressure, dry air isan electric heater-blower.
 26. The bucket truck of claim 25, whereinsaid electric heater-blower further serves as one or more of theinternal air diffuser and the external air diffuser.
 27. The buckettruck of claim 23, wherein said source of high volume and pressure, dryair is a compressor and an air dryer.
 28. The bucket truck of claim 23,further comprising one or more concentrator-diffusers positioned atintervals along the length of the insulated boom section to concentrateair travelling along the exterior surface of the insulated boom sectionand direct it further along the exterior surface of the insulated boomsection.
 29. The bucket truck of claim 23, further comprising an airheater in connection with the source of high volume and pressure, dryair.
 30. The bucket truck of claim 23, wherein said first end of theinsulated boom section is a bottom end of the insulated boom section andsaid second opposite end of the insulated boom section is an upper endof the insulated boom section.
 31. The bucket truck of claim 23, whereinsaid internal air diffuser comprises an annular manifold to direct anddistribute air flow.
 32. The bucket truck of claim 31, wherein theannular manifold comprises one or more nozzles on a surface thereof. 33.The bucket truck of claim 23, wherein said external air diffusercomprises an annular manifold to direct and distribute air flow.
 34. Thebucket truck of claim 33, wherein the annular manifold comprises one ormore nozzles on a surface thereof.